Electro-optical and robotic casting quality assurance

ABSTRACT

This invention relates to improvements in foundry procedures, particularly in-process and post process inspection with electro-optical sensor units. Principally addressed are: inspection of molds and cores to assure correctness and control procedures to abort pouring if the molds are not correct, inspection of cores on the core line, inspection of patterns for sticking sand, inspection of finished castings for extraneous material in passages, excessive or inadequate stock, correct locator relationships, etc., and control of robotic flash grinders. 
     Both fixed and programmably moveable sensors are shown in the context of these embodiments.

BACKGROUND

Modern casting practice has tended toward lighter weight castingsutilizing less metal and capable of withstanding higher stresses. Thismeans that higher tolerance casting procedures must be employed.Furthermore, to improve productivity, a paramount consideration today,procedures must be taken to reduce the amount of scrapage and visualinspection labor that is required in present day foundry practices.There is no sense pouring metal, for example, into a mold that is nogood, only to scrap the casting later.

In addition to that problem, if one is capable of producing scrap, onemust also inspect for this. Inspection costs a lot of money and what isworse is many visual inspection procedures miss the problem which thengets out into the field and becomes a warranty and customer satisfactionproblem of the first order.

Because of the above, there exists a great need in current foundries forelectro-optically based inspection utilizing both fixed optical sensorsand programmable ones capable of being moved to different locations ondifferent parts or to a number of different locations on the same part.The invention is described in several embodiments:

FIG. 1 describes an embodiment for the in-line inspection of high volumedrag molds on a mold line using a nest of fixed electro-optical sensorsof various types with control capability to absort the pour if incorrectconditions are discovered. A recording capability for statistical dataon the molds is also provided.

FIG. 2 illustrates an embodiment utilizing a robotically positionedsensor cluster for performing a similar mold inspection. This inspectionis more flexible and it can programmably check different molds atdifferent locations etc. at a high resolution but, however, at a lowerrate.

FIG. 3 and FIG. 3A are, respectively, plan and side elevational views ofan embodiment employing a fixed type sensing for checking well wallthickness in cylinder block cores on a core line.

FIG. 4 and FIG. 4A illustrate an inspection apparatus for stickers onpatterns on an engine block mold line.

FIG. 5 and FIG. 5A illustrate a programmable coordinate measuring orrobotic type inspection system for castings and in particular cylinderhead castings to determine surface finish, hole diameters, blockedpassages, overall dimensions, presence of proper locator stock etc.

FIG. 6, FIG. 6A, FIG. 6B, FIG. 6C and illustrate various embodiments ofa sensing system for a robotically controlled flash grinder for cylinderheads and other parts.

FIG. 1

FIG. 1 illustrates a system to inspect molds on a continuous mold linefor any or all of the following:

cores are complete (not missing pieces)

cores are properly positioned in drag mold (alignment, height)

sand in molds is correct size and no damage

pins and pin holes in cope and drag mold are correct size and in goodenough condition to allow proper mating.

If conditions above are all good then a signal is given by the system toa down stream operation to pour metal. If not, no metal is poured,saving money is scrap and inspection. Other savings are warranty repairand prevention of machine damage. For example, if cores shift changingalignment can produce cylinder bore walls in engine block which are toothin. If cores are missing or sand is damaged, one can get blocked wateror manifold passages, or too much metal to machine which damagessubsequent machines, lowering productivity.

Basic components of the system are:

(1) One or more image scanners or cameras (solid state matrix diodearray preferred)

(2) Lighting to highlight features where possible, preferably one ormore flashed (strobe) Xenon lamps to "freeze" part in position, sincethe mold line is typically in continuous motion.

(3) Control micro computer, generally reprogrammable for different parts(most lines run with different parts intermixed and/or periodicallychanged).

As shown, engine block casting "drag" molds (1) are moving end to end intheir respective mold cars with cores (2) in place. When pin 5 on dragmold is sensed by tripping beam from sender 3 on receiver 4, any or allof the following steps are performed.

Matrix TV camera 10 and ring flash 11 plus a companion unit at the otherend (not shown) scan pin 6 and/or pin hole for the spacing of the twopins or holes, their roundness and diameter so as to assure correct fitup with the cope mold (to be placed later on top of the drag mold, withthe two halves, cope and drag, making a complete mold ready forpouring).

One of more matrix array or other cameras such as 15 and 16 inconjunction with flashed light sources such as 17, 18, and 19successively flashed, also take in data into micro computer 30concerning core presence, completeness and alignment in the drag mold.Also sand feature data concerning the mold is also taken in.

Because the sand and core features are often uniformly black or lackingcontact lighting angles are chosen so as to create shadows which canyield reliable dimensional data.

Next the micro computer 30 analyzes the data and makes a decisionwhether the mold is OK to pour at a downstream station. Also,quantitative data is built up about each mold used to form a statisticaldata on the various parts and their placement.

In the FIG. 1 system above a complete arrangement of sensors, lightsources, part position detectors etc. and computer equipment has beenprovided to allow the categorization of the molds and the position andcharacter of the cores within them. Clearly, however, not all of thecomponents need be used in any one system. For example, one might justwish to look at the pins in order to say that they were not being worntoo much or conversely one might assume that the pins were okay andsimply look at the same or the core etc.

While FIG. 1 only illustrates inspection of the drag mold, it is clearthat to make a full representation of the complete mold to be poured,one would also like to look at the cope mold which is the upper onebrought down to make a "sandwich." In some lines this is very difficultto do because of the way the lines are constructed and requires lookingup using mirrors with blow-offs to keep sand out, etc. On other lines,however, the cope mold is actually transported face up until the pointto where it is actually turned over and in this case, the mold can belooked at in much the same way and simply tracked so that the correctcope mold inspection is matched with that of the matching drag moldinspection.

Clearly, the arrangement of the light sources and sensor units aboveneeds to be considered for each of the inspection tasks required.Obviously, it may not be true that the same lighting arrangement whichis best for a cylinder head mold and core is also best for the engineblock. Further, both of these might typically be run on the same linetogether. In this case, still more light sources and sensor units wouldbe required so that one could select between them for the best possibledelineation of the sand lines, core position and features. Suchselection is easy with micro computer 30.

While not shown in the drawing, it is clear that the same sensing of thesand or cores could be performed at other locations, for example, on thecore line itself just after the cores have been made and before theirinsertion into the molds. In this case, the missing parts etc. on a corewould surely be desireable to detect at that point before they wereplaced into the mold. Grossly deformed cores would be of course in thesame category. This is illustrated in FIG. 3 which is discussed below.

Regarding the time available, the typical mold lines run fairlyfast--one mold every 10 seconds for example. However, if the edgedelineation is sufficient, the amount of computer time required toextract data can be kept to a minimum. Clearly, one does not have to seeall the possible data points on these molds or cores in order todetermine if they are lined up and in reasonably good shape.

It is not difficult to provide for tracking of the mold car to the pourstation and to control the pouring operation. Naturally, one would liketo keep a tally of those mold cars which have repeat problems in theirpins for example and for this reason, optical or magnetic serial numberson the mold cars would be desirable which could be read out by mold carnumber and associated with the data taken. A sensor for this is shown inthe figure as a device 100 for reading bar code, denoted 101, on theside of the mold car.

The significance of this embodiment should not be underestimated sinceit is capable of inspecting for most of the variables in the castingprocess that would cause the block or whatever other casting to bedefective. The fact that one does not have to pour that mold at leastmeans that the rework cost and the iron cost, to a degree at least, issaved. One has of course had to go through the effort of putting thesand and cores in the mold and one can utilize a robot or othermanipulator to retrieve a good core from a defective sand situation orideally to even reposition the core if it was out of position. Thisconceivably could be done manually after sounding an alarm. Indeed withrobot core placement one could very easily see this system guiding thecore in after first inspecting it.

FIG. 2

FIG. 2 illustrates a alternate type mold inspection utilizing a robotbased sensor ensemble. In this particular example, the molds may beeither stationary or more typically moving on a mold line. If thelatter, the robot control system considers the speed of the line, takingthis into account as it causes the robot to move to various positions onthe mold for inspection.

Considering FIG. 2, as shown, robot 200 is being used to inspect moldsand and cores 215 in mold car 200 moving on the line.

The sensors utilized are xy matrix 225 and optical triangulating rangingsensor 230 of types described in copending application Ser. No. 34,278.Both sensor units are connected along with the robot to the controlcomputer 240.

To utilize the invention it is simply necessary to preprogram in, or forthat matter, teach the robot where on the mold to move the sensor unitsto. The non-contacting optical sensor units then take in the data fromthe mold at the positions in question and are used to determine whetheror not the molds should be poured as above.

Naturally because the robot is completely flexibly programmed, it can beutilized to move the sensor units to different portions of differentmolds as desired when mixed production is being run.

In the copending application Ser. No. 34,278 referred to above, atypical sensor unit incorporating both the triangulation sensor 230 andthe xy camera type sensor units 225 can be used (as shown in FIG. 16 ofthat application). Such a sensor is capable of obtaining completedimensional data about a part very quickly. In a preferred embodiment ofthe invention, the robot would move in a continuous path taking data"on-the-fly" while the mold car moved, or for that matter wasstationary.

One advantage of the robot type, if it can handle the speedrequirements, is that it can move the sensor units up quite close to themold car in a manner which might not be possible for some universalfixture over the line. This allows them to concentrate on certaindetails very accurately. It does however, have the maintenance problemof moving parts etc. where the FIG. 1 version does not.

The robotic programmable version can also inpect different features ondifferent molds of the same type. For example, if block mold number"thirty-one" was shown to have a potential bad pin problem, this couldbe checked each time, but only periodically on the other molds.

FIG. 3 and FIG. 3a

This embodiment illustrates inspection of the sand core of an engineblock casting. As shown in FIG. 3, such a core 250 is composed of sandin thos areas where it is desired to have an open space within thefinished engine block. The obvious two areas are the cylinder areas 251and the various water passages between the cylinders 225 and 256 asshown in the remaining shaded area. Particularly of interest are the"webbing zones" between the cylinders 225 and 256 which, if oversize, asillustrated for cylinder 255, causes insufficient cylinder wallthickness and if undersize, as illustrated for cylinder 256, causesinsufficient water circulation between the bores.

As illustrated this core passes under the sensor camera, differentpictures are taken sequentially of the core areas by trigger means notshown using xy matrix camera to 260 with the core moving on the side byrails 265 and moving on conveyor 270. The various sections indicated at275 are taken and compared to limits. Naturally the presence of allthese given areas can also be determined on any completely misaligned ordefective cores are rejected by reject means for marking means notshown. Optionally additional sections such as 277 can be measured aswell.

Suitable matrix array can be General Electric TN 2500, suitable lineararrays are Reticon 1728H's.

FIG. 4

FIG. 4 illustrates an embodiment of the invention utilized forinspection of patterns for "stickers." The pattern used to make a moldis of polished metal which, under tremendous pressure and heat,compresses the sand and forms the mold. As shown, such a pattern for aVee engine block shown at 500 with projecting sections at 501. Thepattern is in its raised position between cycles.

Between cycles then, it is desired to inspect the pattern to see if anyresidual sand (a "sticker") is sticking to the mold which would cause anindentation in the sand mold and a consequent bulge on the real part.While such sand is typically quite small, it can be a good contrastsince it is black on a shiny background.

To practice the invention, an actuator such as robot arm 520 brings thesensor unit 530 into position inside the machine. The sensor unit 530scans the image of the pattern and determines therefrom if any stickersare present. Because of the presence of sand, etc. falling down from themold, a shutter device 533 is used with the sensor to open it up onlywhen necessary to take a picture. A flashed ring light source 540 isutilized and in general it may be required to utilize still furtherlight sources in order to provide a diffusive illumination of the wholepattern surface, such that bright areas appear bright in the image andthat false dark conditions are not created by having too littlereflected light reach the sensor from the good portions of the metalpattern. Such auxiliary lights are shown as 550 and 551.

A suitable sensor is a matrix array camera GE TN2500.

Instead of shutter 533 one can utilize blow-offs to keep the windowclean and such blow-offs or shutters are utilized to advantage in otherembodiments shown in this invention since foundry atmospheres typicallyhave sand and other contaminents in the air. This has proved to be noreal problem except in general, on those sensor windows which pointupward.

It is also feasible to have the sensor camera 530 located outside thechamber, and a mirror (not shown) placed therein. Indeed, in certainmold conditions, it is not even required to move the mirror in and outsince a position in the line is available where the pattern movesthrough. This is shown in dotted lines in FIG. 4B where the camera unit555 and light source are located outside the mold area with a fixedmirror, 560, itself equipped with blow-offs 570. It should be noted thatthe same questions of looking upward at the pattern also applies tolooking at the cope mold as in FIG. 1. This cope mold is typicallyinverted as well as many lines although in this case the pattern can bethe one on the bottom. In either case, it stands to reason that hisinvention is useful in checking both patterns and molds produced bysame.

FIG. 5 illustrates a robotic based inspection system according to theinvention, while shown with a polar coordinate robots, cartesiancoordinate systems including more conventional coordinate measuringmachines (CMM) can be employed.

As shown, a part, in this case a cylinder head 600 mounted on optionalturntable 601 is being insected for various features and conditions. Theinspection is performed primarily by robot 610 under control of computer615. This robot contains one or more eletro-optical sensors such asensor 616 which in this case is a solid state TV camera composed oflens 621 and matrix array 620 used to form an image of the part whenilluminated either by external lighting (not shown) or by flashed lightsource 625 carried with the sensor.

It should be noted that any other sensor described in any of thereferenced applications can be used. For example, FIG. 16 of Ser. No.34,278 referred to above also shows a similar sensor but equippedadditionally with sensors for range. Multiple sensors can be usedsimultaneously, if desired.

Also of great value is the use of interchangeable or turret tooling.This is illustrated here in the form of different sensor modules 626,627 and 628 located in "tool" holder 629. The robot can pick these upand utilize them for various other types of inspection. For example,sensor 626 can be a surface contouring sensor, sensor 627 can be asensor for inspecting for porosity in bores, and sensor 628 can be evena contacting sensor, for example a contact optical type used for certaindimensions.

In the application shown, a somewhat smaller second robot 630 is alsoshown. This robot also can be equipped with sensors such as 641 and 642located in its tool holder denoted 643. However, at the momentrepresented by the diagram, a light source module 640 rather than asensor module has been picked up by this robot and is being pointed in aone end of a hole of said casting 650 such that the light emerging fromthe other end 651 can be detected by matrix array 620 and the blockagetherein determined.

It can be seen that this system is capable of programmably providingvirtually all necessary inspections on a finished casting or for thatmatter a core or mold etc. It is primarily meant for off-line usealthough, again, in-line checking can also be performed if onealternates the checks from part to part or if the line is sufficientlyslow given the number of checks involved.

It should be noted that the matrix array 620 can be used not only tocheck the surface features and dimensions of the part, but also to readcertain bar codes (such as 101 in FIG. 1) that might be written on apart by laser or other marking units.

In this case, a laser marking unit as shown at 660 is used for marking aserialized bar code on a painted surface of the casting as a result ofthe various dimensions and data taken by the robotic system. The markingunit receives its information from control computer 615. This data canthen be fed to subsequent processes in the machine line etc. based ondimensional data and other things taken at this station.

Other methods other than laser markers can be used but a laser markerhas been found to produce extremely clearbar codes readable by remote orhand-held laser and wand scanners which can be economically used atother positions throughout the plant.

This is also highly useful for inventory control and other purposes.

While not shown for clarity, other robots or automation can be used toturn the part over as well as to look at the side which is obscuredlaying on the turntable 601. Indeed, either of the robots present can dothe turnover by substituting suitable tooling for a sensor. Naturallythe turntable itself can be used to present other sides to the robot orrobots utilized and there is no limit to the number that can be utilizedto perform this inspection. Whatever is convenient or cost effective canbe used. Each robot present too can draw its sensor tooling from thesame storage area as well.

One very important inspection on a cylinder head is to inspect thecombustion chamber shape and the volume thereof or the shape of thechamber 670 relative to certain locating surfaces such as 671. Thischeck can also be performed at this station and results recorded ifdesired with the serial number put on by the laser.

Furthermore, the sensing unit of FIG. 5 can be used before machining toquality castings, both dimensionally and for passage blockage, presenceof excess flash, certain types of visible porosity and the like. Theinvention can also be used as will be described below at this stage forautomatic defect inspection via x-ray or penetrant inspections. It isnoted that in this case, that the penetrant inspection can also beperformed with the hardware here disclosed as with now be described.

One of the most interesting aspects of this invention is that the dataobtained in this inspection unit of FIG. 5 and others can be coded andpassed forward to the subsequent machining processes. This isparticularly interesting when a serial number is put on as shown with alaser (or other suitable means) since this allows the part to goanywhere in random fashion and still carry the data with it in the maincontrol computer associated with the serial number.

If the casting data is also carried, it can be used to adjust themachines for different casting conditions allowing otherwise scrap partsto be utilized and preventing the machining of parts which would turnout to be scrap. This is a particularly important feature when onethinks of the automated factory where very little inspection andmanpower is available for checking the parts going into the machines. Itis also noted that this adds a capability really not possible with humaninspection in that all pertinent aspects of the casting can be checkedand their data fed to the machine tools.

Suitable parameters to adjust on the tools would certainly include theposition of the casting locators relative to other points to be machinedwhich would then tell the machine just how far in to cut. If excessmaterial was present, the machine control computer could take this intoaccount and allow a longer cycle time or a tool change as needed. Thesame would hold true if it is know that the tools are dull and thatthere is a particularly large amount of material to cut. Further, thatpart could either not be cut at that pass and placed aside until moretime was available, or the tooling could be changed. Naturally, if thereis excess flash present, the machine could further be instructed to takethat flash out automatically. Conversely, if the flash was in the way ofthe location, this head could be put over to a rework area.

In terms of defects, such as porosity, cracks and so on, naturally thesewould be prevented from going to the machine automatically and theknowledge that the part contains such defects would be stored in thecomputer and utilized to control that part to ensure that it did notreach the machining cycle without correction.

As has been mentioned, automated penetrant inspection can indeed bedone. For example, in the case of FIG. 5, we may consider that each ofthe robots could be holding, in this case, an ultra violet projector 616and a TV camera 640 for example, or vice versa. In any case, the TVcamera would be positioned to zoom in one certain critical areas ofinterest that were illuminated with the ultra violet lamp. By having theultra violet lamp positionable, a large amount of light can beconcentrated in a small area. Similarly, by having the field of view ofthe camera unit directed at the fluorescent indications of cracks etc.when treated with penetrant type preparation such as "Zyglo" or"Magneglow" (trade marks of the Magneflux Corp), a much highermagnification of the view is provided.

Accordingly, it is the purpose of this invention to provide for arobotically positionable light source and a camera unit to selectivelyand sequentially illuminate different parts of a casting to determinethe defects therein. As shown in FIG. 5, the source and detecting unitcan be separately positionable, however, and this can be useful forobtaining different lighting levels of various curvatures of the part.However, it is also within the realm of the invention to utilize thelight source and the detection unit on the same robot or otherpositioning arm. Suitable signal processing for the crack typeindications which can occur is disclosed in the co-owned applicationSer. No. 34,278 referred to above.

It is also within the purview of this invention to provide a fullyautomated line robotically configured for the inspection of castings fordefects. This is shown in FIG. 5B and illustrates some of the conceptsjust discussed as well. For the purpose of illustration, the robot inthis case moves the part into varying attitudes and positions, with thesensing and other equipment fixed.

As shown, it is desired to inspect a connecting rod casting 700. FIG. 5Billustrates an interesting example of a complete robotic inspection cellfor connecting rod castings. As shown, the connecting rod castings 700comes in on track 701. It is grabbed by robot 701 on its large end andplaced in penetrant preparation tank 705 where it is treated by knownmethods with penetrant and either magnetized or not in order to causethe penetrant to adhere to the cracks if any in the material.

The part is then moved from the penetrant bath to a penetrant inspectionstation 708 comprising light source 710 and TV camera 715 hooked tocomputer 720. This computer 720 is also to be connected to the maincontrol computer 730 of the system. This TV picture is such thatindividual zones of the rod can be sequentially examined with the robotpositioning the rod in front of the camera in more or less knownorientations.

After this inspection the part is moved by the robot arm, which is againshown in dotted lines (given the fact that it is moveable to eachposition), to an electro-optical measurement station 750 where differentportions of the part are categorized for dimension such as the borediameters, the flash amounts, oil hole bosses, flange widths etc.

The part is then moved to an optional coding station including a lasermarking unit 755 where a paint spray unit applies a paint code and thelaser marking unit 755 then burns this away with a bar code representingthe various dimension and defect data taken at the previous stations.This typically could be a serial number for the part.

It is noted that the laser mark can go into the metal and be recoverableeven if the paint is removed. The parts are then loaded over ontowalking beam transfer unit 780 which moves them to a machining areawhere they are machined.

Intermediate between stations 705 and 708 or between stations 705 and750 can be a wash unit such as indicated at 790 and 791, respectively,to remove the penetrant chemicals from the part surface.

The robot as shown can take one rod and move it in succession but giventhe fact that the penetrant preparation 705 can require some timeperiod, may well simply pick up a previously prepared rod from eachstation and bring it to the next. It is noted of course that theautomation for this does not have to be a robot. Other types ofautomation can be used, however, the robot is very useful forpositioning the rod in many degrees of freedom in front of the varyinginspection stations as well as into the baths etc. and into theload/unload as well.

Another application of this invention is in the control of robots forworking on castings. This includes one of the most obnoxious jobs in thefoundry, viz., the grinding of flash off of castings. This is a noisy,hot, somewhat dangerous job that generally requires considerable amountsof premium labor because of the personnel rotation that must be used toprevent over exposure to the job.

In trying to automate this, one is immediately faced with the fact thatin order to make cycle time, one must remove flash only where the flashis and not all over the part. Otherwise, no sort of programmable roboticsolution can be entertained because it would simply be too slow if onetried to go everywhere on the part functional surfaces, whether therewas flash there or not.

Accordingly, it is an object of this invention to provide a controlledsystem for "cleaning" castings. For example, in FIG. 6A, there is showna robotic grinder which is going to remove the flash of a robot asfollows:

Robot 800 contains the grinding wheel (or alternatively the mill) 801,which is used to remove the flash stock 805 from the cylinder head bankface 806, with the cylinder head, in this case, being held in the hand810 of robot 811. It is noted, however, that the cylinder head could bestatically clamped to a plate without use of the second robot 811.However, the second robot provides a much more general solution sincemore degrees of freedom are available. It also stands to reason thatsomething anyway has to bring the part in and out, and this can be therobot itself. The parameters to be determined are the height, breadthand length (in the direction out of the plane of the diagram) of theflash and the location of the flash along the face.

Another problem is that there can be flash in the ports and this cannotbe removed by the grinder 801 but must be removed instead by toolingsuch as a power chisel. For this reason the grinder tooling itself,denoted 801, is shown as being mounted on a receptacle or carrier 815and it is noted the tooling for the grinder can be replaced into rack820 which contains a power chisel tooling 821 whose end 822 also fitsinto receptacle 815.

In the first mode of operation, one can first grab suitable sensortooling such as 825 also located in the tool change rack. This sensortooling can typically be matrix diode array (solid state video) cameracapable of digitizing the image of the cylinder head flash 805. In thismode of operation, the robot first gets the sensor and essentially usesthe sensor in conjunction, if desired, with robot 811 to look over thezone of the bank face 806 and memorizes where the flash is. It then goesback, changes the tooling and proceeds to grind the flash where it hasbeen memorized. In this way, the working environment of the grinder orchisel for that matter, is kept removed from that of the sensor.

FIG. 6B illustrates another version showing a combination grinder andsensor unit. In this case, the grinding wheel 801 is accompanied with asensor unit 830 (which is very much like that of FIG. 16 of Ser. No.34,278 referred to previously) in that it provides for both rangemulti-axis measurement of the part location. In this case, the part face806 is seen to have a bump of flash 835 whose length and width isdetected using the matrix array 840 on whose face the image of surface806 is formed by lens 841 when illuminated lamp 860. For the range (orbump height) dimension in the z axis, a separate light source 850 isemployed this time with a diode laser to put a spot or strip of lightonto the part as fully disclosed in Ser. No. 34,278 via thetriangulation principle.

In this embodiment, a shutter system 855 opens up on command of thecontrol computer of the robot 856 and allows the light from the diodelaser 850 and the illumination lamps 860 to illuminate the part takingin the data as to its locations. The shutter then closes down and therobot moves the grinding wheel in to take off that piece. When thisoperation is completed, the grinding wheel is moved back out of the way,the shutter can be opened and a verification that this flash was removeddone. Unlike the embodiment of 6A, this particular unit has immediatefeedback of data as to what happened and does not rely on storing of thetotal coordinates of the part, only those in the local area to beworked. Also, of course, it does not have to go back and get changetooling for the sensor, although it would for the chisel which could beutilized in the same way as the grinder along with the sensor.

One can see that both these applications are quite workable. Theremaining one shown in FIG. 6C is to utilize a system which has theminimum time delay between sensing and grinding. In this case, a smallshutter unit with a fiber optically remote image sensor is providedwherein a dual grinding wheel is utilized with a sensor in between. Thisunit is capable of almost simultaneous monitoring of the surface whilegrinding. It is only necessary to slightly back off the grinder, open upthe sensor and see what happened since the sensor field of view extendsto both sides. As shown dual grinding wheel 900 rotates about its axisto grind the face 801 as before. In this case, a fiber optic lightmodule, indicated at, for example, 905, illuminates the surface using aremote lamp (not shown). This fiber optic light module can easily be1/4" or less in width requiring only that amount of space between thegrinding wheels. Shutter units 865 with positive air pressure behindthem are also utilized as is a shutter unit 875 on the receiving fiberoptics 880 used to image the zone of the surface 801 illuminated.

While this embodiment has been described with respect to a single fiberwith a 2 axis image, it is clear that another fiber may be used to bringin a light spot just as from laser 850, in FIG. 6B, to provide atriangulation range determination as well. If lens is used to image thelight from the surface onto the end of the fiber optics receiver unitthereby getting the data back to a removed TV camera, matrix diode arrayor the like. The weight of the dual grinding wheel and fibers is verylight and can easily be carried by any robot is question for thisapplication.

FIG. 6D shows yet another grinding arrangement. In this case, the end ofarm tooling 910 contains built within it a camera unit containing matrixarray 911 and lens 912 forming an image of the part 801 as before. Inthis case, however, a programmably moveable grinding wheel mount 919around axis 920 is utilized which swings grinding wheel 925 out of theway of the image while the part 801 is being viewed. After the image isdigitized, as previously described, the grinding wheel 925 is broughtdown in to contact with the part and the operation performed.Interestingly, this tooling can also have, optionally swinging out ofthe other way in the other direction, a power chisel 926, indicated indashed lines, which then can be used to go after the heavier flash orinside the ports. Naturally this can swing out of the way in anydirection and other means than swinging out, such as shuttles etc canalso be provided. This approach then is perhaps the ultimate since itallows the simplest sensor design while still retaining almostconventional type tooling.

It should be noted that it all cases the tooling of this application hasbeen shown moving with the robot, it is also obvious that the tool andsensor apparatus can be fixed in one location with a robot such as 811used to solely manipulate the part into position against the tool/sensorcombination. The whole key here is that, robotically, the relationshipof the sensor to the part as well as the tooling to the part iscontrolled.

Besides the grinder shown in FIG. 6D, it is also possible to use othertools for flash trimming and deburring such as milling cutters and thelike. It is also noted that force sensors can be provided on the robotarm such as 815 to detect the forces coming back from the part and fromthat also determine when correct or incorrect conditions are present.

While a grinding wheel has been shown, it is clear that milling, wiringbrushing and other casting cleaning processes can also be done in anidentical manner and it is clear that by use of the fibers with varioustooling, such as chisels etc., one can built in the means to control therobots. For example, the same interchangeable tooling applicationsdescribed above can also be used to couple light into the power toolingshown here to provide sensing capability.

The embodiment of FIGS. 6, 6B, 6C and 6D relates to a novel concept.Electro-optical sensors can be built into tools in a particularly easyway using fiber optics.

We now explore this concept further not only relative to castingfinishing tools, but all tooling in general. Tools with this capabilitycan be used to qualify the part to be worked, finding the work, orinspecting the work during or after using the tool.

Note that `light` in this disclosure covers all electro-magneticwavelengths x-ray to millimeter wave. However, near uv, visible and nearinfra red sources are preferred.

In FIG. 5 it is important to note the function of the second robot 650in positioning light source 640. The programmable light sourcepositioning provided can be crucial not only in illuminating holes, butin accentuating certain edge features for dimensional analysis, e.g. bysensor 620. For example, in position 655 (shown in dashed lines) therobot can illuminate the edge indicated at 656 with much more contrastthan can light source 625 carried with the sensor. This can be useful tothe utmost part dimension accuracy, not just on castings but finishedparts and other objects as well.

It is noted that rather than 2 robots, one for sensor, the other for thelight source, it is often useul to have one robot with two arms, eachseparately programmable.

What is claimed is:
 1. A method for automatically controlling machiningof a casting in an automated process for producing a plurality ofcastings, said method comprising the steps of:painting a backgroundpaint onto the casting, removing said paint with a laser to provide abar coded serial number, electro-optically inspecting said casting andproducing output data in accordance therewith, storing, in memory, saidoutput data produced by inspecting said casting and said serial numberand, automatically reading said serial number at a machining station toprovide access to said casting data in memory, and automaticallycontrolling machining of said casting by a machine at said machiningstation in accordance with said casting data.
 2. A method ofautomatically finishing castings comprising the steps of:using roboticmeans to provide relative positioning of a plurality of castings, insequence, with respect to an electro-optical triangulation rangingsensor and a electro-optical imaging sensor, using said imaging sensorto determine at least one dimension of the casting being sensed, usingsaid ranging sensor so as to provide at least one distance measurementrelative to the casting being sensed, determining from the output ofsaid sensors the location of the portion or portions of the casting andthe amount of finishing required, and automatically causing suitabletools to finish said casting at the determined location or locations. 3.A method for automatic control of a casting machining operation, saidmethod comprising:utilizing robotic means to provide relative movementof an electro-optical trianglating ranging sensor and an electro-opticalimaging sensor with respect to a casting so as to provide, using saidranging sensor, at least one distance measurement relative to the partsof the casting and to determine, using said imaging sensor, at least onedimension of the casting; processing the outputs of said triangulatingranging sensor and said imaging sensor to produce distance measurementdata and casting dimension data; and using said distance measurementdata and said casting dimension data to control the operation of amachine for machining the casting so as to provide machining of thecasting in accordance with said data.
 4. A method as claimed in claim 3wherein said imaging sensor comprises a photodetector matrix array.
 5. Amethod as claimed in claim 3 further comprising using shutter means toprotect said imaging sensor, said shutter means being opened when adimension determination is being made.
 6. A method as claimed in claim 3wherein said ranging sensor and said imaging sensor are mounted on acommon robot arm for movement therewith.
 7. A method as claimed in claim3 wherein said ranging sensor and said imaging sensor are moved relativeto the casting.
 8. A method as claimed in claim 3 wherein the movementof said sensors is along at least two axes.
 9. A method as claimed inclaim 3 further comprising comparing the amount of excess material at alocation on the casting a predetermined maximum and bypassing machiningof the casting when the predetermined maximum is exceeded.
 10. A methodas claimed in claim 3 wherein said casting is to include at least onepassage therein and said imaging sensor senses the presence or absenceof such a passage.
 11. A method according to claim 3 wherein saidcasting is marked with a serial number and said data stored along withsaid serial number.